Thermostatic circuit breaker



June 30, 1931.

H. MAPLE THERMOSTATIC CIRCUIT BREAKER Original Filed Sept. 25, 1922 3 Sheets-Sheet 1 INVENTOR.

For H MHPLE.

MM M

A TTORNEYS.

June 30, 1931. R. H. MAPLE 1,812,162

THERMOSTATIC CIRCUIT BREAKER Original Filed Sept. 25,1922 3 Sheets-Sheet 2 IN VEN TOR.

R07 H. MHPL E.

ATTORNEXIS.

Jun 30, 1931. MAPLE 1,812,162

I THERMOSTATIC CIRCUIT BREAKER Original Filed Sept. 25, 1922 3 Sheets-Sheet 3 INVENTOR. E'or b6 NHPZE.

BY 1 y ATTORNEYS-Q Patented June 30, 1931 UNITED STATES PATENT OFFICE V ROY H. IAPLE, OI INDIANAIOLIS, INDIAl VA Application filed September 25, 1922, Serial No. 590,287. Renewed November 10, 1980.

This invention relates to improvements in, tional view of the same. Fig. 7 is an end elecircuit breakers.

The chief object ofthis invention is to provide a circuit breaker which is of low capacity so that the same is adapted to replace the present fuse construction.

Another object of the invention, and probably the most important, consists in constructing the device in such a manner that the usual line switch associated with the fuse is replaced by a combination thermally controlled switch, which is positively protective in its action in that as long as the load is on the line the circuit cannoth permanently 1| closed. v

Another object of the invention is to construct the device in such a manner that the elements thereof are not releasable when subjected to excessive vibration.

A further object of the invention is t construct the same in such a manner tha the device may be enclosed to prevent any access whatsoever to the mechanism, unless the complete switch mechanism is entirely removed from the circuit by prior removal from its'support.

The full nature of this invention will be understood from theaccompanying drawings and the following description and 80 claims.

In the drawings Fig. '1 is a top plan view of the invention showing the same as a two pole switch construction with one switch construction in the closed circuit position and the other in the open circuit position. Fig.2 is a cross sectional view. Fig. 3 is a similar view showing the thermally controlled parts in the open circuit position and the manually controlled parts in the closed position. Fig.

49 4 is'a similar view showing the thermally controlled parts in the closed circuit position and the manually'controlled parts in the open circuit position. Fig. 5 is a top plan view of the thermal member and the catch and latch vational view of the same. Fig. 8 is a cross sectional view showing the details of mounting a portion of the switch mechanism. Fig. 9 is atop plan view of a portion of the cover and supporting base showing the means for securing the same together. Fig. 10 is a central sectional view taken on the line 1010 of Fig. 9 and shows the same construction. Fig. ll'is a perspective view of the thermostat support and travel limit means. Fig. 12 is a perspective view of the thermostat protective cover.

In the drawings 10 indicates an insulating base provided in the present instance with a pair of thermally controlled devices, and. a pair of switches associated therewith, the switches and the thermally controlled device being manually operable by a common member, in a manner hereinafter to be described. While a plurality of similar units are herein illustrated, the-invention is not to be limited to a plurality, but may be constructed of a single thermally controlled device and a single switch or a plurality of each. Since the thermally controlled devices are substantially identical, a description of one will suflice for them both. Reference may also be had to the co-pending application Serial No. 555,274, and in said application various details and the specific operation of the thermally controlled means are described in detail. A standard 11- having the base portion 12 suitably supports the stud '13 which is a'djustably positioned in said standard by means of a tool engageable portion 14and thevlock nut 15. The portion .14 permits the stud to be engaged by a suitable tool and said stud may be turned in the bracket into the desired position to secure a predetermined amount of movement uponthe passage of a predetermined current through the thermally responsive elementherein shown in the form of a thermostat 16, which is coiled and 15 associated therewith. Fig. 6 is a side eleva; has its inner end 17 secured in the slotted end of the stud 13, see Figs. 5, 6 and 7. When stud 13 is adjusted it is permanently secured as by soldering. The other end of the thermostat is provided with a catch portion 18. having the retaining edge 19 and the supporting portion 20. T e supporting portion 20 is not only secured to the front end of the coil thermostat, but also secures one end of a shunt or pig tail member 21. The particular 1 of the thermostat.

taining member 18 iswithdrawn 'rearwardly or rather outwardly from the roller 22Iand iv the movement is also such that the member 18 is moved downwardly as well; The'roller' rests upon the edge 19 until it is free from the retaining member 18 and, thereafter is released, and moved upwardly with a support associated with the pin 23 and hereinafter to be described.

The base 12 supporting the standard 11. is- ,suitably secured to the insulated base 10, at

at least three points indicated by the numerals 24. This three-point support insures absolute rigidity of the standard 11, whereby exactness and certainty F of operation is secured. The base 12 is extended, as shown clearly in Fig. 1 and carries a terminal 25. whereby current carrying means is secured to said base; This terminal 25 is connected to the loadside of the circuit.

The particular switch construction controlled bv the thermal construction comprises a plurality of'spring contact fingers 26-suit- 1 ably secured, as shown in Fig. 2, to the base 10 at 27 and by the bolt and nut means 28 and 29 respectively. One of the spring fingers 26 carries an arc resisting protective member 30. The springfinger contacts 26 are connected to the live side of the, line of the circuit.

Upon the particular pivot 31 suitably secured tothe base 10 by means of the-cotter pins 32 and is a, U-shaped plate 34 having the side, portions 35 which are apertured to receive the pivot 31. Between the ears or sides of the plate 34 and concentric with the pivot, is a coil spring 3.6, whichhas one end 37 bearing upon said'side'member' 34 and the other end 38 suitably secured to or hearing upon-the base 10 so that said coil spring nor- .inallyljteiids'to maintain-the plate member- 34. in open c rcuit position. The side wall 350i the plate member 84 pivotally supports at 39; a roller 40. Herein a pair of said rollers is il-lustrated in tandem, but it is tobe understood'that if desired a'roller may be associated with each of the side walls 35, or the number of rollers may be increased or diminished or other contact are resisting means substituted therefor. gages the arc resisting contact member 30 and contacts the arcwhen the switch is open .or closed. The plate 34 is provided withtwo forwardly extending arms 41 which are twisted and drilled to form a pair of bearings for the pin 23 carrying the roller 22. When the plate member 34 is caused to close the circuit by means of-the roller engaging the contact 30, current is transmitted from said.

plate member 341to the plate 12'by means of the pig tail or shunt construction 21 which is electrically connected with the plate 34. By reason of the coil construction the thermostat moves outwardly to permit the roller 22 to pass and be latched thereb 1 Suitable means for manually closing the thermally controlled switch comprises an msulating block 42 each end of which is grooved at 43 to besecured to a U-shaped handle 44 having the arms 45 which are.provided with trunnions46 ivotallysupported by the cotter pins 47. ne trunnion 46 is extended and forms a-handle 48 whereby the insulated member may be moved into engagement with the plate 34 for closing the thermally controlled switch. The side walls 35 of the late 34 engage the insulated member 42 as s own clear- The roller 40 enly in Fig. 2 and as shown in Fig. 4, said insulated member 42 is adapted to move the Y plate 34 into closed circuit position.

Reference will now be had to Figs. 1 to 4 inclusive and Fig. 8. In said Figs. a U- shaped current conducting member 50 is simultaneously secured to the base 10 with. the spring finger 26 andis in electrical connection therewith. The U-shaped member 50 is provided with two inwardly extending parallel ends which pivotally sup rt a switch plate 52. The switch plate 52 is herei ,p in shown cut away: at 53,'to form an arcuate edge for clearing coil spring 36 when latching the thermal switch member. Positioned in alignment with the switch plate 52, is a spring contact of any usual or preferred form 54, which is suitably securedto a 'contact strip 55 by means of'the boltand nut 56 and 57 respectively, thereby maintaining said switch contact and the contact strip 55 upon the insulated base 10. The contact strip 55 terminates in a terminal 58 substantially sim-' 'ilar to the terminal 25 and said terminal 58 is adapted to be connected to the current su ly line and, therefore, the live side of t e me.- The contact switch plate 52 is provided wltha projecting portion 59 and the insulated member'42 is provided'withan open ing 60 adapted to receive the projecting'portion 59.

From the foregoing it will be observed that the insulating member 42 is rigidly secured in .7 position by means of the U-shaped handle 44 m and the contact plate or plates 52. It will also be noted that in orderto close the ther-- mally controlled switch it is necessary to open the circuit between the switch plate 52 and the contact 54, and after said switch has been closed in order to supply current to the circuit, the handle 44 must be moved into the opposite direction, as shown in Figs. 2 and 8, and close the circuit through the switch plate 52 and contact 54, If the-abnormal circuit conditions persist, current will again pass through the thermostat and release the switch controlled thereby and thereby prevent the passage of current to the load. Thus, the load will be protected at all times. In order to close the thermally controlled switch, after t-he second operation thereof, it is again necessary to open the main line switch including the plate 52 and contact 54 and thereby open the whole circuitin order to close the thermally controlled switch. So long as the abnormal condition exists in the load circuit it is impossible to supply current to the load circuit without having-the thermally controlled switch operate.

With the foregoing construction it will be realized that the device is absolutely fool proof so far as a single line is concerned and the device is adapted to replace the fuse and switch construction now employed as standard wiring members. It will, of course, be, understood that the capacity of the switch is determined by the kind and amount of material and the construction of the thermostat. All of the current passes through the thermostat, although, if desired, the thermostat may be shunted and a portion of the current pass through ,the shunt.

In the drawings there is illustrated a double switch construction which may be utilized in direct current wiring or single phase alternating current wiring system. The generic idea of the invention is shown herein, which may be briefly stated as non-closing, load in the line switch, may be extended to multiple phase alternating current systemwithout de parting therefrom, but such an extension cooperative arrangement between the phases forms no part of the present invention, but is reserved for subsequent application.

A further feature of the invention is to make the same fool proof, in that it is always desirable to prevent tampering or unauthorized interference with the switch construction. A cover is provided which is suitably apertured to permit the handle 48 to extend through said cover and the cover 70 is provided with a flange portion 71 and, as shown clearly in Figs. 2, 3, 4, and 10, the base 10 is apertured at,72 and in said aperture there is secured a bolt 7 3 which is associated with the nut 74 which is provided with a flat face, said face engaging upon the side of the cover 70. The nut thus is held against rotation by the cover. Likewise the cover, when secured to the base 10 by means of the bolt 73, cannot be removed from said base without first removing the base 10 from its support. Under the underwriters present wiring requirements, a

grounded cabinet must be provided and said rounded cabinet is so constructed that the ine wire and the load wire must bedisconnected from the switch construction supported by the base 10 before said base can be removed from said cabinet. The removal of the cover 70 from the base 10, to permit access to be had to the switch construction.

necessitates the removal of base 10 from its support to get at bolt 73. Only a competent electrician will follow the foregoing inconvenient procedure, and this is what the device is intended to insure, as well as automatically protect the load circuit.

In order to fully protect the catch, thermostat and the mounting thereof, a cap is provided, said cap comprises a top portion 80,

'a pair of adjacent depending walls 81 and'an apertured side wall 82 with a retaining portion 83. Said cap construction is adapted to substantially enclose the thermostat'member 16 and yet permit the latch to be associated with the catch portion. The nut 15 secures the cap 80 to the stud 13, and preferably is soldered to the standard 11 when said stud 13 and nut 15 are soldered thereto, thereby forming a rigid joint.

To prevent excessive movement of the thermostat, thus permanently deformingthe same, a stop member 85, see Fig. 11, is provided which is suitably secured to the plate 12 and ion limits movement as indicated in Figs. 1 to i 4 inclusive.

v The invention claimed is: f

1. Anelectric switch, construction includ ing incombination a plurality of thermally operable switches, each having a current conducting and movable switch controlling member, a plurality of manually operable switches each in series with one of the other switches, anda single common means difi'erentially associated with both types of switches at thesame time.

2. In an electric switch construction the combination of a. plurality of manually controlled switches, a plurality of thermally controlled switches each having a current conducting and movable switch controlling member and being each in series with one ofthe other switches, and a single common means associated with all of said switches ing the same or all the manually operable switches for closing the same.

'4. An electric switch construction including in combination a thermostatically controlled switch having a'current conducting and movable switch controlling member, a

manually operable switch in series. therewith,

v and'means associated with both switches but at different times for closing the same.

5. An electric switch construction including in combination a plurality of therm0-' statically controlled switches each having a current conducting and movable switch controlling member, a plurality of manually operable switches, each in series with one of 'the other switches, and a single common means differentially associated with bothtypes of switches at the same time.-

6. In'an electric switch construction the combination of a plurality of manually controlled switches, a plurality of thermostatically controlled switches each having a current conduct-ing and movable switch controlling member and being each in series with one of the other switches, and a single common means associated. with all of said switches for closing the same.

7. In an electric switch construction the combination of a plurality of manually controlled switches, a plurality of thermostatically controlled switches each having a current conducting and movable switch controlling member and being each in series with 4 '38 one of the other switches,and a manually 0 rable single means simultaneously-assoc1ated with all the thermostatically con- 'trolled.switches for closing the same or all the manually operable switches for closing the same.

8. In a combination'of an enclosing casing,'a thermally expansible member, means for limiting the expansion movement of said thermally" expanslble member, and a protective cap for said thermally 'expansible member.

1 9. In a thermally controlled switch the combination of an enclosing casing a thermally. expansible member, a supportlng member,,threfor, mean's'for limiting the expansion movement of. said thermally expansiblev member and supported by said supporting -'member, and a protective cap for said thertrolling mally expansible cap also supported by said supporting member.

10. In a thermally controlled switch the combination of a current conducting and 11. In' a thermally controlled switch the thermally controlled switch the combination of acurrent conducting and movable thermally ex ansible switch controlling member, a switch member. controlledby said thermally expansible member, a second switch member positioned adjacent the first mentioned switch member, a roller means carried by saidfirst mentioned member for engaging said second mentioned switch member, and are resisting material upon said. second mentioned switch member for the purpose described. 7 I

' 12. In a thermally controlled switch the combination of a current conducting and movable thermally expa-nsible switchcontrolling member, a switch member controlled by said thermally expan'sible member, a. second switch member positioned adjacent the first mentioned switch member, a plurality of'rollers carried by said first mentioned member forsuccessively engaging said second mentioned switch member;

1-3. In an enclosed switch the combination of a casing, a support, a switch thermostat, and a housing therefor including a pair of adjacent sides, a top and an apertured side for the reception of a thermostat support.

' 14. In an enclosed switch the combination of a casing, a support, a sw1tch thermostat, and'a housing therefor including a pair of adjacent sides, a top and an apertured side for the reception of a thermostat support,

and a retaining portion associated with the top and one of the sides positioned as a fourth side. l

15. In a thermally controlled switch the combination of a current conducting and movablethermally actuated control member, a. catch controlled thereby, a pivotally supported plate provided with a pair of projecting portions in spaced relation, ga pivotpin supported by said projecting portions, and a roller supported by said pin in the s ace be tween sald catch. v

16. In a switch construction the combination of a pivotally sup orted switch mem ber, an insulating mem r extending trans versely of said switch member, a U-shaped portions and engageable y said rod .pivotally' supported and adapted tostraddle said insulating transverse member, and a pin and slot connection between said switch member and said insulating transsecured between said switch member and said second mentioned transverse member.

17 In a switch construction thcombination of a'. plurality of-pivotally su ported "switch members, an insulatin a U-shaped rod .-'pivotally' supported and adapted to straddle said insulating transverse member, and a' in and slot oonnectionbemem r -ex-- tending transyersely of said switch members,

verse member, whereby the latter is rigidly tween each of sa dswitch members and said transverse member, .whereby the latter is rigidly between said switch member and the U-shaped rod and the switch members are simultaneously movable. 18. An electric switch construction including a'plurality of thermally releasable switches, each including a current conduct? ing and movable switch controlling member, a plurality of other switches, each other swltch being in series with one of said thermally releasable switches, and a common closing means for successively and simultaneously closing difi'erent types and each type of switches respectively.

In witness whereof, I have hereunto aflixed my signature.

' ROY H. 

